I know some of the pieces, and most of the composers/arrangers. You can't go wrong with Shaw/Parker, Copland, Rutter, or just about any madrigal. They work well with SSA voices.
Is the Copland piece an arrangement, or an original? Do you know? He did some marvelous arrangements of old hymn-tunes that are hard to beat.
The Copland is an arrangement of an old ballad:"On the lake where drooped the willow..." Sound familiar?